Adjustable eraser attachment



July 4, 1939. w w, sMlTH 2,164,433

ADJUSTABLE ERASER ATTACHMENT Filed March 28, 1938 Patented July '4, 1939 UNITED STATES PATENT OFFICE- 6 Claims.

My invention is an adjustablev eraser attachment, and has for its general object the production of a simple and efllcient device which may be easily applied to any pencil crother body.

One specific object is to provide an eraser adjusting nut into which the eraser may be withdrawn, which nut may be conveniently removed from its support for the insertion of another eraser when the previous one is worn down so as to be no longer convenient or useful.

A second object is to'produce an adjusting device, the parts of which are yieldingly retained in operative relationship, with the result that they are assembled by simply applying them to each other with a slight pressure, and are disassembled by a slight strain in the opposite direction.

In the accompanying drawing,

Fig. 1 is an elevation of the device mounted upon a pencil; A

Fig. 2 is an enlarged section von line 2-2 of Fig. 1, the metal being shown in abnormal thickness for clearness of illustration;

Fig. 3 is a section of the nut detached;

Fig. 4 is a section of the tubular body detached;

and

Fig. 5 is a transverse section on line 5-5 of Fig. 2.

In said drawing, III is a tube having threads II at its lower end of a size adapted to be screwed upon the upper end of a plain lead pencil or other body 9. On one side, the tube is cut in a well known manner, and a portion is bent inward as shown to form a stop I2 which will limit the position of the device on the pencil.

At a convenient point, which may be opposite the stop I2, there is another cut, and a portion of the tube is bent outward to form a spring bulge I3. Theupper end of the tube I0 has a longitudinal slot I4 which may extend to about the position shown in Fig. 4.

Mounted on the tube III is a sleeve I5 which has `a portion bulged outward as shown'at I6 to form an inner annular recess adapted to receive the spring bulge I3 on tube III. These parts are so related to each other that when the sleeve` I5 is pushed over the upper end of the tube I 0, the bulge I3 will be pressed inward to let the parts assume the position shown in Fig. 2. In this position, the sleeve may be turned freely on the tube, and the spring I3 willact -to prevent the longitudinal displacement of the sleeve on the tube. moderate force and permit the sleeve to be withdrawn when such act is desired.

u There is provided an eraser l1 of a diameter The spring I3, however, will yield to al (Cl. 1Z0-38) which will t easily into the tube I0. 0n the inner end of the eraser is a thin metal ferrule or cap I8 which may be secured in place in any convenient manner, as by indentations. I9. On the exterior of the ferrule is a projection or tooth 20 whichmay be aseparate piece or may be a portion of the ferrule cut and bent outward. 'This projection projects thru the slot Il in tube I0 and engages screw threads 2| formed in the interior of the sleeve I5. These screw threads 10 merge into the interior concave o1' the bulge Il, and a small channel `22 is formed in the interior of the lower end of sleeve or nut I5 to allow for the passage of projection 20 when withdrawing the sleeve or returning it to place. The ferrule l5 is in fact simply a connecting means for securing the projection 20 to the eraser I'I.

In assembling the parts, the eraserfl is placed in the tube with the projection 20 extending thru slot I4, and resting at the bottom end thereof. 20 The sleeve I5 is then placed over the tube and turned until the groove or channel 22 comes to the projection 20 and said projection passes therethru. This movement of the sleeve causes it to embrace the spring I3. 25

In operation, the sleeve or nut I5 is turned to cause the eraser I1 to project more or less as may be desired. When the eraser is worn down until it is no longer satisfactory, the sleeve is pulled olf over the slight resistance of spring I3, and 30 the remnant of the eraser is thrown away. A new eraser is then substituted in the manner before described. This operation involves only a few seconds of time. When the pencil becomes too short for convenience, the tube III is un- 35 screwed and attached to a new pencil.

From the foregoing it will be evident that the present device is extremely simple, consisting of no more than two tubular pieces yleldingly retained together, and an eraser having a projec- 40 tion by which said eraser is longitudinally adjusted by merely turning one tubular piece with respect to the other. Also, that the normal friction between the spring bulge I3 and the interior of the bulge I6 on sleeve I5 will serve to 45 prevent pressure on the eraser from causing it to recede in the tube III when being used for erasing.

What I claim is: y

1. An eraser provided with a projection on its 50 side, a tube adapted to receive said eraser and having an open ended guide for receiving said projection, and a nut adapted to engage said projection and moveit in said guide. I

2. An eraser provided with a projection on its 55 side. a stationary guide-in the form of a slot with its upper end open for receiving said projection, and a rotatable sleeve mounted upon-said guide and having an internal thread engaging saidprojection to move it.

3. A tube adapted to be secured to a pencil and having an intermediate part thereof bent to form a spring, means rotatably mounted upon said tube and engaging said spring so as to be yieldingly retained `from axial movement thereon, and an eraser supported within the tube and axially adjustable by turning said means on the tube.

4. In an adjusting device, a sleeve having an interior screw thread merging into an interior enlargement near one end and a channel beyond the enlargement to permit a tooth to pass from the outside of the device to said thread, a tube within said sleeve and having a portion thereof 20. bent to form a spring retaining device located within said enlargement, and an adjustable body located within the tube and having a tooth extending thru an opening in the tube to engage the screw thread in said sleeve. v

5. In an adjusting device, an adjustable body having a projection secured on a side thereof. an enclosing tube having an open ended slot thru which said projection extends, and a rotatable sleeve mounted upon the tube and hav- WALLACE W. SMITH. f 2o 

